This invention relates to apparatus and methods for closing intravascular defects and occluding blood flow. In particular, it relates to closing septal defects or holes found between the walls of the four heart chambers and occluding blood flow in sections of a patient""s circulatory system.
The heart chambers include left and right atrial chambers in the upper portion and left and right ventricular chambers in the lower portion. Defects in these walls can be formed congenitally or can develop later in life. An atrial septal defect (hereinafter, xe2x80x9cASDxe2x80x9d) is found between the right and left atrium and a ventricular septal defect (hereinafter, xe2x80x9cVSDxe2x80x9d) is found between the left and right ventricles. The defect allows blood to be shunted between the chambers, causing the heart""s pumping action to be inefficient, and creating a risk of embolization (the circulation of an abnormal particle through the bloodstream).
A similar defect is the patent ductus. The patent ductus is a pre-birth opening between the aorta and the pulmonary artery. This opening usually closes naturally, but may remain open and cause oxygenated blood to flow back into the lungs. Another defects are the ductus arteriosis and the patent foramen ovale (hereinafter, xe2x80x9cPFOxe2x80x9d). At least fifty percent of stroke patients under 55 years old have a PFO.
Therapeutic treatment of these defects normally requires extensive surgery. For example, treatment typically requires open heart surgery, cardiopulmonary bypass, and stopping of the heart. During treatment, the defect is sewn shut by applying a thin patch over the hole. Less invasive methods for closure of these defects, such as intraluminal transcatheter approaches, for example, but provide unreliable delivery and deployment. A transcatheter apparatus has a large delivery profile that limits application of the method to young patients and makes it difficult to match the apparatus to the intracardiac or extracardiac cavity and can result in thrombosis, emboli, or dislodgement due to interference with blood flow.
It is also known that septal holes cause strokes by shunting clots from the right atrium to the left atrium. From the left atrium, a clot can go to the brain. Some holes are asymptomatic and should still be closed to prevent future stroke. Patients having asymptomatic defects would benefit from a low-invasive and reliable treatment apparatus and method.
In addition to the treatment of septal defects, it is often desirable to occlude blood flow in a section of the circulatory system. Occlusion can control internal bleeding and buffer pressure in the vicinity of an aneurysm.
Therefore, it would be desirable to provide apparatus and methods for treating septal defects, such as ASD, VSD, and PFO, that function at least as well as the proven surgical thin sewn patch, but which are less invasive.
It would also be desirable to provide reliable apparatus and methods for delivery of intraluminal transcatheters and deployment of septal defect devices and plugs.
It would be more desirable to provide these apparatus and methods such that the delivery profile is small and such that they can be used to treat patients of a wide range of ages.
It would be further desirable to provide septal defect devices and occluding plugs that can be properly matched to the intracardiac or extracardiac cavity.
It would be still further desirable to provide apparatus and methods for percutaneous delivery and deployment of occlusion devices for blocking blood flow in various sections of the circulatory system.
Therefore, it is an object of the invention to provide apparatus and methods for treating septal defects, such as ASD, VSD, and PFO, that function as well as the proven surgical thin sewn patch, but which are less invasive.
It is also an object of the invention to provide reliable apparatus and methods for delivery of intraluminal transcatheters and deployment of septal defect devices and plugs.
Additionally, it is an object of the invention to provide these apparatus and methods such that the delivery profile is small and such that they can be used to treat patients of having a wide range of ages.
It is a further object of the invention to provide septal defect devices and occluding plugs that can be properly matched to the intracardiac or extracardiac cavity.
It is a still further object of the invention to provide apparatus and methods for percutaneous delivery and deployment of occlusion devices for blocking blood flow in various sections of the circulatory system.
In accordance with one aspect of the present invention, a plug is provided for closing an aperture in a wall of a patient""s body cavity. The plug includes: a frame that has a central axis; a first plurality of fingers configured to engage an interior surface of the body cavity wall; a second plurality of fingers that are attached to the first plurality and are configured to engage an exterior surface of the body cavity wall; and a plugging structure. The fingers can be positioned substantially circumferentially about the central axis. The plugging structure is attached to the frame and spans the aperture when the plug is in position. Furthermore, cross-sections of the frame that lie in a plane substantially perpendicular to the central axis are substantially discontinuous in order to enable the plug, and particularly the frame, to conform to the perimeter, or contour, of the aperture.
According to another aspect of the invention, a plug is provided that has a perforated tubular portion having a longitudinal passage. Any cross-section of the perforated tubular portion taken along a plane perpendicular to the passage is substantially discontinuous to allow confirmation of the portion to perimeter of the aperture. The plug has a plurality of fingers extending from each of the two axial ends of the perforated tubular portion. Preferably, any cross-section of the fingers taken along a plane perpendicular to the passage is also substantially discontinuous. The plug also has a plugging structure as described above.
In yet another aspect of the invention, an occlusive device is provided for occluding blood flow at a treatment site. This device is similar to the preceding plugs, but has fingers extending from only one axial end of the perforated tubular portion. During operation, these fingers anchor the device to the internal surface of a blood vessel.
According to still another aspect of the invention, methods for plugging an aperture in a wall of a patient""s body cavity is provided. The method includes positioning a conformable plug in the aperture, conforming the plug to the aperture, and securing the plug in the aperture. It will be appreciated that the steps of conforming and securing could occur at the same time. Methods for occluding blood flow are also provided.